Intensity-modulated and image-guided radiation therapy for head and neck cancers

Radiation therapy is a key component of the multidisciplinary treatment of head and neck cancers (HNC), which are ideal tumors for intensity-modulated radiation therapy (IMRT) because of their location and intimate relationship to the surrounding critical structures. Several institutional studies have suggested that IMRT is superior to conventional radiation therapy in salivary preservation and holds promises for improved locoregional control of these tumors. Small randomized studies have supported the role of IMRT in reducing xerostomia and possibly improving quality of life. Target delineation for IMRT in these tumors is complex and requires detailed knowledge of head and neck anatomy and pathways of tumor spread. The advent of image-guided radiation therapy offers a new innovation that can refine IMRT delivery even further. This article focuses on the issues surrounding IMRT target delineation for typical HNC presentations and a discussion on the role of FDG-PET imaging in HNC treatment planning.